Dolphin Echolocation

Dolphin Echolocation

It is believed that dolphin echolocation was the result of evolution over time. This process allows for them to send out sound waves that are like a click. When those sounds hit an object it bounces back vibrations to the dolphins. This allows them to identify where objects are located. It also gives them information about the location of the object and some indication of the shape and size of it.

The amount of time it takes for the sound waves to come back help them to identify the distance. The longer it takes for the sound waves to return, the more distance between them and that given object. Many experts have long looked into echolocation, but there is still plenty that isn’t known about it. The first person to really look at it closely and to document the findings was Jacque-Yves Cousteau. He wrote about it in a book that was published in 1953 called The Silent World.

It has been identified by some humans that they can actually feel the buzz from the dolphin echolocation when they are in the water around them. They can’t hear it but they do feel it and that is a very interesting feeling to identify and address. It is also a huge mystery and one more part of this process that has the experts mystified.

Dolphins make a sound that travels quickly through water. This sound is bounced back and the information decoded in the Dolphin Melon.

What is known is that dolphins have the ability through echolocation to have a sound frequency of 120 kHz and for humans with excellent hearing it is about 20 kHz. Even though dogs and cats have better hearing than people, it still doesn’t compare to the dolphin. Dogs have about 45 kHz and cats have about 65 kHz.

Dolphins have a melon in the head that allows for the information to be transmitted. The transmitter for it is found in the lower jaw, and the teeth of dolphins work like antennas to send the signals. It is a very complex element of their survival and their anatomy that has many experts in awe.

It is believed that the whistling sounds dolphins are known to make also are part of echolocation. They are able to pass air through the blowhole through air sacs. If you take a balloon, partially blow it up, and then slowly let out air, this is similar to the same results they get. Behind and below the blowhole is a bi-sonar signal generator. The vibrations here against the blowhole is what allows echolocation to be initiated, referred to as the echolocation pulse.

As mentioned, the lower jaw plays a role in all of this. It is filled with fat and for the dolphin, plays the same role as the outer part of human ears do. This is how they are able to figure out the direction a given sound is coming from. It is also important to point out that sound is able to travel 4 ½ times faster in the water than out of it.

What you may not know is that high frequency sounds don’t travel very far in the water. Low frequency sounds have more energy so they are able to travel a greater distance. Most of the time, dolphins will get the best results with echolocation when the object is from 16 feet to 656 feet from them.

A common question then is if dolphins have such good hearing through echolocation, why do they often collide with boats and other vehicles in the water? There has been plenty of research about this and the problem isn’t with the dolphins. Instead, it stems from the fact that there are plenty of negative environmental concerns out there that they have to contend with. They can include sonar testing, offshore drilling, commercial fishing activities, and more.

The result of such noise in the environment for dolphins is upsetting. It can cause them to lose their hearing over time. It can also result in them becoming disoriented and not be able to successfully navigate through the water for migration and other purposes. In the most severe cases, dolphins have died due to hemorrhaging inside of the ear. All of this is concern for the future of dolphins, and some of the conservation efforts in motion address these issues.

Sometimes, you may also hear echolocation referred to as bi-sonar. There are quite a few animals out there that use it to help them find out what is going on in their environment based on the echoes that are returned. However, it is believed that the dolphin has one of the most advanced and sophisticated systems.

Even though we understand the basics of how it works, there is plenty more information that experts need to find out to fully understand it. Perhaps one day we will have the technology to learn much more about it.